Guard for punch presses



W. A. WalsMAN Zim GUARD FOR PUNCH PRESSES Filed Nov. l2, 1954 2 Sheets-Sheet l I NVE/JTD@ b /LL/fw @W5/M- h5 4T TDW/EK W, H936, W. A. WHESMAN GUARD FOR PUNCH lRESSES Filed Nov. 12, 1954 2 Sheets-Sheet 2 CTI Patented Mar. 10, 1936 UNITED STATE ATET OFFICE l5 Claims.

This invention relates to guards for punch` presses and similar machines. It is customary to provide a punch press with a guard arm which i's usually mounted for oscillatory movement across the front of the press in timed relation to the movementJ of the ram so as to positively move the hands of the operator out of the path of the ram as the latter approaches the work. It is important that the guard arm shall complete its operative movement, that is, its movement across the path of the ram, while the ram is still a substantial distance from the work. The continued movement of the ram toward the work then imparts a further movement to the guard arm which often causes the free end of the arm to project an objectionable distance beyond the side of the press, this being particularly true in large presses in which the ram is very wide with relation to the overall width of the press and has a relatively long operative movement.

One object of the invention is to provide means for so operating a guard arm that it will be moved only a relatively short distance after it has completed its movement across the path of the ram or other reciprocatory member.

A further object of the invention is to provide means for causing the guard arm to move a relatively great distance during an initial portion of the operative movement of the ram. and to then move a relatively short distance during a subsequent portion oi the operative movement of the ram.

A further objeet of the invention is to provide means for imparting a relatively short reverse movement to the guard arm after it has moved beyond the path of the ram and before the ram has completed its operative movement.

A further object of the invention is to provide a simple and eicient mechanism' for imparting the desired movements to the guard arm.

A further object of the invention is to provide means for so mounting and operating the guard arm that it may be caused to oscillate in planes spaced dilerent distances in front of the ram.

Other objects of the invention will appear as the mechanism is described in detail.

In the accompanying drawings Fig. l is a fron-t elevation, partly broken away, of a punch press equipped with invention; Fig. 2 is a plan View of a portion of the mechanism shown in Fig. l; Fig. 3 is a side elevation, partly broken away, of the press and guard arm shown in Fig. 1; Fig. 4 is a sectional detail View of the mounting` for the guard arm; Fig. 5 is a transverse section taken on the line 5 5 of Fig. 4 and looking in the direction of the arrows; Fig. 6 is a detail view of the connecting rod; and Fig. '7 is a detail View of the means for adjusting the length of the connecting rod.

In these drawings I have illustrated one em- 5 bodiment of my invention and have shown the same as applied to a punch press of a well known type. It will be understood, however, that the invention may take various forms and may be applied to punch presses, or other similar ma- 10 chines, of Various kinds.

In the particular embodiment here illustrated the invention is applied to a vertical press comprising an upright frame l0 having a Work supporting table il which may support a die I2. A 15 ram i3 is mounted for reciprocatory movement in the frame and is adapted to carry a punch or forming die lli. The ram is operated by a crank shaft l5 mounted in the frame and provided at one end with a fly wheel l5. A guard is mounted zo on the press for movement across the path of and in front of the ram and is operated in timed relation to the movement of the ram to positively move the hands of the operator out of the path of the ram before the latter completes its operative or downward movement. The press as shown is of a well known construction and need not be described in further detail.

In the present construction the guard is in the nature of an arm l1 pivotally mounted at one 30 end cn the frame of the press and so arranged that its lower or free end will sweep across the front of the press when oscillatory movement is imparted thereto. Preferably this guardA arm is mounted on an axis near the top of the press and substantially midway between the sides thereof.

It will be noted that in the particular press illustrated the ram occupies a large portion of the overall width of the press and the free end of the guard arm must be moved across the entire width of the ram during an initial portion of the movement of the ram, that is, the operative movement of the arm must be completed while the ram is still spaced a substantial distance from the work. The movement of the guard arm being controlled in accordance with the movement of the. ram it will be obvious that the continued movement of the ram will tend to move the guard arm beyond the side of the press and if this latter movement is in the same ratio to the movement of the ram as the initial movement of the guard arm is to the initial movement of the ram the guard arm will project a relatively great distance beyond the side of the frame. This, of course, is objectionable.

vFor the purpose of preventing the guard arm from being projected too far beyond the side of the press after it has completed its operative movement I have provided means for so actuating the guard arm that only a relatively short forward movement will be imparted thereto after it has completed its forward movement across the path of the ram. This may be accomplished in various ways but I prefer to employ an actuating member which is pivotally supported at one end on an axis xed with relation to the frame and is operatively connected at its other end with the guard arm. Suitable means are provided for moving this pivoted member about its axis in accordance with the movements of the ram and it is so arranged that when the ram is in its retracted or uppermost position the pivoted member will extend upwardly and will be approximately parallel with the guard arm. Consequently during the initial downward movement of the ram the upper or outer end of the pivoted member will move in an arc transverse to the guard arm and will impart a long movement to the guard arm in proportion to the movement of the ram. As the ram continues its downward movement the arc in which the outer end of the pivoted member travels will assume a vertical position more nearly parallel with the guard arm and consequently the movement imparted to the guard arm by the pivoted member will gradually decrease and after the free end of the guard arm has moved beyond the path of the ram only a relatively short forward movement will be imparted thereto. If desired. the operating means for the pivoted member may be so arranged that the final movement of the ram will carry the outer end of the pivoted member downwardly beyond its horizontal position, thereby imparting a slight reverse movement to the guard arm during this nal movement of the ram. When the ram moves upwardly the guard arm will rst be moved forwardly as the pivoted member assumes a horizontal position and will then be moved in a reverse direction to its initial position.

In the present construction the pivoted member is shown as an arm i8 the outer end of which is pivotally connected with the adjacent end of a second arm I9, the other end of this second arm being pivotally connected with the guard arm. The two arms, |8 and IS, thus form a toggle which connects the guard arm with a xed part of the press. As here shown, the arm I8, which may be called the actuating arm, is pivotally mounted on a clip 20 which is mounted upon an upright rod 2| for adjustment lengthwise thereof and is held in adjusted positions thereon by a set screw 22.

The second arm I9 of the toggle is pivotally mounted on a clip 23 mounted on the guard arm I1 for adjustment lengthwise thereof and held in adjusted positions by a set screw 24. The toggle may be actuated in accordance with the movements of the ram in any suitable manner but, in the form here illustrated, it is connected with the ram itself by a connecting rod 25 which is pivotally connected at its upper end with the toggle and is pivotally connected at its lower end with the ram. Preferably a bearing block 26 is mounted on the pivot pin 2'! which connects the two arms of the toggle and is arranged between those arms and provided in its lower portion with a substantially spherical cavity 28 adapted to receive a spherical head 29 carried by the upper end of the connecting rod 25. A bearing block 30 is rigidly secured to the ram and is provided in its upper portion with a substantially spherical cavity 3| to receive a spherical head 32 on the lower end of the connecting rod. Thus the connecting rod has a universal joint connection with both the toggle and the ram so that it can not only accommodate itself to the movements of the toggle but the upper portion thereof can move forwardly and rearwardly with relation to the ram for a purpose which will hereinafter appear. The connecting rod is preferably longitudinally adjustable and in the form shown comprises a tubular upper member 33 in which is slidably mounted a lower portion 34, means being provided to rigidly connect the two parts of the rod in adjusted positions. In the present instance, the connecting means comprises a coil of wire 35 mounted about and adjustable on the tubular member 33 and having downwardly projecting arms 36 the lower ends of which are turned inwardly to form prongs 31. The tubular member 33 is provided in each side with a series of openings 38, and the lower member 34 is provided with a transverse opening 39 adapted to be located in alinement with any pair of openings 38 in the tubular member and when so alined the prongs 31 of the connecting device may be inserted in these openings to rigidly connect the two parts of the rod, the arms 36 of the connecting device preferably being resilient to retain the prongs in the openings.

The connecting rod is of such a length that when the ram is in its uppermost or retracted position the toggle will be broken or collapsed upwardly, as shown in Fig. 1, and as operative or downward movement is imparted to the ram the toggle Will be extended and movement thus irnparted to the guard arm. The rst extending movement of the toggle will impart a long movement to the guard arm with relation to the movement of the ram and as the toggle approaches its fully extended position this movement will decrease so that after the guard arm has completed its operative movement only a relatively short forward movement will be imparted thereto. In the arrangement shown the toggle is of such a length that when fully extended it will cause the lower end of the guard arm to project only a very short distance beyond the side of the frame, as shown at B in Fig. 1. However, the arm will be moved to this position before the ram has completed its operative movement and the further or nal movement of the ram will break or partially collapse the toggle in a downward direction, as shown at C in Fig. l, thus imparting a short reverse movement to the guard arm during the nal movement of the ram. When the ram moves upwardly the toggle will be rst extended, thus moving the guard arm forwardly from position C to position B, and will then be broken or collapsed in an upward direction to fully retract the guard arm to its initial position, as shown at A in Fig. 1.

The guard arm may be mounted on the frame of the press in any suitable manner. In the present construction a bracket 40 is rigidly secured to the top of the frame, extends forwardly therefrom and has an upwardly extending part 4|. A supporting member is mounted on this bracket for adjustment about a transverse axis and carries the guard arm Il. In the construction shown the supporting member is shown in the form of a yoke `comprising a transverse portion 42 and rearwardly extending arms 43, arranged on opposite sides of the upright portion 4| of the bracket and pivotally connected therewith by means of adjustable pivot pins or screws 44 which are seated in tion to the respective bearing members.

pivot bearings inthe respective edgesof thepart 4|! of the bracket. Rigidly secured tothe transverse portion 42 of the yoke is a` laterally extending bar 45 tothe outer end of which is attached the upper end' of the vertical rod 2| to which one end of the toggle is connected. Mounted in the part 4| of the bracket and extendingforwardly therefrom is a pivot pin 46' which` is here shown as a bolt having nuts 41 on the respective ends thereof. This pivotV pin extends through and projects some distance beyond the laterally extending bar 45 and has mounted thereon, adjacent to the bar 45, a lateral bearing member or disk-48 which is held against rotation, preferably by means of dowel pins 49 carried by the yoke and extending through bothr the bar 45 and the disk 48. Aasecond lateral bearing member or disk 50' is mounted on the forward portion of the pivot pin and is held in spaced relation to the rear bearing member by a spacing sleeve which, in the present instance, is` formed integral with the forward disk 50. When the nuts on. the pivot pin are tightened down the bearingl memberswill be rigidlyheld in properly spaced relation and both the bearing `members and the pivotzpin will be rigidly secured to the yoke. If desired, a dowel pinl 52 may be inserted inthe bearing member'48andthe-spacing sleeve to positively hold. these parts against relative rotary movement. The guard arm has at its upperend a hub portion 53 which is' mounted on the spacing sleeve 5| between the bearing membersand has iiat bearing surfaces in opposed rela- The bearing members are spaced apart such a distance with relation to the thickness of the hub 53 as to permit the free rotary movement of the hub on the spacing sleeve but to hold the same against axial or tilting movement. Mountedin the transverse portion 42 of the yoke and extending rearwardly therefrom are two adjustable members 54, such as screws, the rear ends of which contact withI the upright portion 4| of the bracket above and below the pivot-al axis of the yoke'and hold the yoke and the supporting assembly, of which it .forms a part, in fixed relation to the bracket. By adjusting these screws the yoke and the pivot pin. may be adjusted to various angular positions with relation to the bracket, thereby causing the lguard. arm to move in different planes, spaced different distances from the front of the ram.

It will be noted that the bar 45 which carries the arm supporting rod 2| is mountedv on the yoke 42 for movement therewith and consequently when the supporting member or yoke isadjusted about its axis the rod 2| and the toggle are adjusted rtherewith so that the toggle always remains in proper relation to the pivotal axis of the guard arm, and the universal connections between the connecting rod 25 and the. ram. I3 and the toggle permit the upper portion of this connecting rod to move forwardly and rearwardly to accommodate itself to the adjustments of the guard arm..

While I have shown and described one embodiment of my invention I wish it to be understood that I do not desire to be limited to the details thereof as various modifications may occur to a person skilled in the art.

Having now fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a machine. comprising a frame, a reciprocatory member, and a. guard arm pivotally mounted on said frame for movement transverse to the path of said reciprocatory member; means fior. adjusting said' guard arm to cause the same tomove in different planes, a toggle having one arm connected with said guard arm and having itsother' end connected with a xed support, a pivot: pin connecting the two arms of said toggle, abearing block carried by said pivot pin and having a forwardly facing spherical cavity, a bearing block carried by said reciprocatory member and having arearwardly. facing spherical cavity, and a. connecting rod having at its ends spherical headsv mounted in the respective cavities.

2. In a machine comprising a frame, and a member mounted for reciprocatory movement on said frame; a yoke mounted on said frame for movement about a horizontal axis, a pivot pin carried by said yoke and extending transversely to said horizontal axis, bearing members mounted on said pivotpin and spaced one from the other, a guard arm having a hub supported by said pivot pin between said bearing members, a bar secured to. said yoke and extending laterally therefrom, a rodv carried by said bar and extending lengthwise of the path of said reciprocatory member, a toggle connected with said rod and said guard arm, and means for operatively connecting said toggle with said reciprocatory member.

3. In a machine comprising a frameand a member mounted for reciprocatory movement on said frame, a bracket carried by said frame, a yoke mounted on said bracket for movement about a horizontal axis, a pivot pin mounted on said yoke and extending transversely to said horizontal axis, a guard arm mounted on said pivot pin for movement about the axis thereof, means adjustably mounted' on said yoke and cooperating with said bracket to adjust said yoke about said horizontal axis, and means actuated in accordance with the movement of said reciprocatory member to impart oscillatory movement to said arm.

4. In a machine comprising a frame, and a member mounted for reciprocatory movement on said frame; a bracket carried by said frame, a yoke mounted on said bracket for movement about a horizontal axis, a pivot pin mounted on said yoke and extending transversely to said horizontal axis, a guard arm. mounted on said pivot pin for movement about the axis thereof, studs adjustably mounted in said yoke and engaging said bracket above and below said horizontal axis to control the position of said yoke with relation to said bracket, and means actuated in accordance with the movement of said reciprocatory memloer to impart oscillatory movement to said guard arm.

5. In a machine comprising a frame, and a member mounted for reciprocatory movement on said frame; a yoke mounted on said frame for adjustment about an axis transverse to the path of said reciprocatory member, a guard arm supported by said yoke for oscillatory movement about an axis transverse to the axis of said yoke, means for adjusting said yoke about its said axis to alter the position of said guard arm with relation to said frame, and means actuated in accordance with the movement of said reciprocatory member to impart oscillatory movement to said guard arm.

6. In a machine comprising a reciprocatory member and means for actuating the same, a guard mounted for movement in a plane transverse to and in front of the path of said reciprocatory member, an actuating arm pivotally mounted at one end on a fixed part of said machine and extending lengthwise of the path of said reciprocatory member when the latter is in its retracted position, a second arm pivotally connected with the free end of said actuating arm, extending alongside thereof and connected with said guard, and means connected with said reciprocatory member and acting on the connected ends of said arms to move said arms into substantially alined positions transverse to the path of said reciprocatory member during the forward movement of said reciprocatory member and to thus impart to said guard arm a transverse movement which progressively decreases with relation to the movement of said reciprocatory member.

'7. In a machine comprising a frame, a reciprocatory member and a guard arm pivotally mounted on said frame above said reciprocatory member for movement in a plane transverse to and in front of the path of said reciprocatory member; a toggle having its arms pivotally connected respectively with said guard arm and with a normally stationary support spaced laterally from said guard arm, said toggle arms being movable into rearwardly converging positions extending lengthwise of the path of said reciprocatory member and into substantially alined positions transverse to said path, a two part rod having its upper part connected with said toggle and having its lower part connected with said reciprocatory member, and means for adjustably connecting the two parts of said rod to vary the length of the same.

8. In a machine comprising a frame, a reciprocatory member and a guard arm pivotally mounted on said frame for movement in a plane transverse to and in front of the path of said reciprocatory member; means for adjusting said guard arm with relation to said frame to cause the same to move in different planes, a toggle having one arm connected with said guard arm and having its other arm connected with a normally stationary support, a rod connecting said toggle with said reciprocatory member, and means for adjusting said rod with relation to said reciprocatory member about an axis substantially parallel with the plane of movement of said guard arm to accommodate the same to the adjustment of said guard arm.

9. In a machine comprising a frame and a member mounted for reciprocatory movement on said frame, a supporting structure, means for mounting said structure on said frame for adjustment about an axis transverse to the path of said reciprocatory member and substantially parallel with the front of said machine, a guard arm mounted on said supporting structure for oscillatory movement about an axis transverse to the first mentioned axis, a member carried by and adjustable with said supporting structure, said member extending lengthwise of the path of said reciprocatory member and being spaced laterally from the pivotal axis of said guard arm, a toggle having one arm connected with the last mentioned member and having its other arm connected with said guard arm, and a rod connecting said toggle with said reciprocatory member.

10. In a machine comprising a reciprocatory member and means for imparting movement thereto, a guard mounted for movement transversely to and in front of the path of movement of said reciprocatory member, an actuating member pivotally mounted at one end on said machine, normally extending lengthwise of the path of said reciprocatory member and movable about its pivotal axis to a position transverse to said path, means for operatively connecting the other end of said actuating member with said guard, and means actuated in accordance with the movement of said reciprocatory member to move said actuating member from said lengthwise position to said transverse position and to impart to said guard transverse movement which progressively decreases with relation to the movement of said reciprocatory member as the path of movement of said other end of said actuating member gradually approaches a line parallel with the path of said reciprocatory member.

11. In a machine comprising a reciprocatory member and means for imparting movement thereto, a guard mounted for movement transversely to and in front of the path of movement of said reciprocatory member, an actuating member pivotally mounted at one end on said machine, normally extending lengthwise of the path of said reciprocatory member and movable about its pivotal axis to and beyond a position at substantially right angles to the path of said reciprocatory member, means for operatively connecting the other end of said actuating member with said guard, and means actuated in accordance with the movement of said reciprocatory member to move said actuating member from said lengthwise position to and beyond said right angle position and to thus impart to said guard transverse movement which progressively decreases with relation to the movement of said reciprocatory member as said actuating member approaches said right angle position and to move said guard in a reverse direction as said actuating member moves beyond said right angle position.

12. In a machine comprising a reciprocatory member and means for operating the same, a guard mounted for movement transversely to and in front of the path of saidl reciprocatory member, an actuating arm pivotally mounted at one end on a fixed part of said machine and extending lengthwise of said path of said reciprocatory member when the latter is in its retracted position, a second arm pivotally connected with the free end of said actuating arm, extending lengthwise of said path alongside the first mentioned arm and connected with said guard, and means actuated in accordance with the movement of said reciprocatory member to move said arms into substantial alinement with both arms extending transversely to the path of said reciprocatory member, during the forward movement of the latter, to impart to said guard a transverse movement which progressively decreases with relation to the movement of said reciprocatory member as said arms approach their alined positions.

13. A guard for a machine having a reciprocatory member comprising a guard arm mounted for movement transversely to and in front of the pathI of said reciprocatory member, a toggle having its arms pivotally connected respectively with a normally stationary support and with said guard arm and arranged for movement to a substantially collapsed position in which both arms thereof extend lengthwise of the path of said reciprocatory member and to an extended position in which both arms thereof extend transversely to said path, and means actuated in accordance with the movement of said reciprocatory member to move said toggle from said collapsed position to said extended position and to impart to said guard arm transverse movement which progressively decreases with relation to the move- 'ment of said reciprocatory member as said toggle approaches its extended position.

14. A guard for a machine having a reciprocatory member comprising a guard arm mounted for movementl transversely to and in front of the path of said reciprocatory member, a toggle having its arms pivotally connected respectively with a normally stationary support and with said guard arm and arranged for movement to a substantially collapsed position in which both arms thereof extend lengthwise of the path of said reciprocatory member and to an extended position in which both arms thereof extend transversely to said path, and means actuated in accordance with the movement of said reciprocatory member in a forward direction to move said toggle from said collapsed position to said extended position and then beyond said extended position to partially collapse the same and to thus impart to said guard arm transverse movement Which progressively decreases with relation to the movement of said reoiprocatory member as said toggle approaches its extended position and to move said guard arm in a reverse direction as said toggle moves beyond its extended position.

l5. In a machine comprising a frame, a reciprocatory member and a guard arm pivotally mounted on said frame above said reciprocatory member for movement transverse to and in front of the path of said reciprocatory member, a toggle having the inner ends of its arms pivotally connected one to the other and having the other ends of said arms pivotally connected respectively with said guard arm and with a normally stationary support spaced laterally from said guard arm, said toggle arms being movable into rearwardly converging positions in which both arms extend lengthwise of the path of said reciprocatory member and into substantially alined positions in which both arms extend transversely to said path, and an actuating member connected at one end with the inner ends of said toggle arms and at its other end with said reciprocatorv member to actuate said toggle.

WILLIAM A. WIESMAN. 

